Sure-Electronics.com class d amps

[kellyinvestor]

Does anyone have any experience/opinion on this amp? spec sheet

[Neil Davis]

This was discussed briefly under the thread "Class D on ebay". Nobody in that thread had bought one yet--just guesses as to what chip is used. The single supply suggests a TI chip, but it's got an analog input, which means it probably isn't TI.

I put one on order Oct 26. When it comes in I'll dissect it and post results.

[BWRX]

According to the drawing there is only one large device under the heat sink. I would guess that it might be a Sanyo STK series chip.

[buzz1939]

I'm not going to try to take the heatsink off, but here are some photos. It'll be a while before I can really give it a listen, but it works and has me curious.

The main chip is one large device.

Photos of Sure 4 Channel Amp

[Ouroboros]

Almost certainly a Sanyo STK428-xxx 'Ice-Power' module. I've tested their two-channel module (STK430-428) and it's a nice performer, though the frequency response alters noticeably with load impedance.

[buzz1939]

FWIW - pdf with product info on STK428-600 2 channel modules - just for the general description

[Ouroboros]

Though this one looks like a single-supply (+24V) version. (My Sanyo data for this range is a couple of years old and doesn't show a full-bridge, single-supply. single-rail module at that time.)

[Ouroboros]

Sorry, I meant that my old data doesn't show a full-bridge, single supply, 4-channel unit!

[audio1st]

Is this it, or half of it anyway ?
http://www.comprel.it/scheda_prodott...t/news1476.pdf
PS I ordered one and a 24V switch mode power supply and they arrived today. Will have a listen at the weekend..

[Neil Davis]

Originally posted by buzz1939
I'm not going to try to take the heatsink off, but here are some photos.

Hmmm...I would have taken off that heatsink within 5 minutes of opening the package. Inquiring minds need to know!

Mine was supposedly shipped on Nov 1 but it hasn't shown up yet.

[Sherman]

Just ordered one of these myself. I've got a couple PS to test with but if I like it I'll likely end up building a supply.

[buzz1939]

Originally posted by Neil Davis


Hmmm...I would have taken off that heatsink within 5 minutes of opening the package. Inquiring minds need to know!

Mine was supposedly shipped on Nov 1 but it hasn't shown up yet.

I guess I wasn't curious enough, I didn't want to mess with potentially stripping and replacing the thermal paste or whatever might be in there. At least until I've had a chance to listen to it for a while.

Mine was also shipped the 1st - I think they finally got them in stock then - and arrived in Boston on the 6th, kind of surprising.

[Ouroboros]

If the power-amp package is the same as the other Sanyo STK428 range, then taking the heatsink off won't help! My STK428-430 only has the markings on the underside of the package. The top side is all exposed metal to thermally couple to the heat sink.

[kellyinvestor]

I'm thinking about using one to run two dvc subs for my home theater, what do you guys think?

[Tekko]

Too low power.

[kellyinvestor]

claims to be 400w

[buzz1939]

That's usually measured at a much higher frequency, IIRC. 1 khz or so. And with more distortion than you'd really accept. Very different results at low frequencies on this one.

[DreadPirate]

I asked the eBay seller what manufacturer made that chip and the response was that it was "custom."


Dear xxx,
Thanks a lot for your letter. This amplifier assembled a custom module, did not use amplifier chips. Feel free to contact us if you have any questions.
Best wishes.
Sure Electronics

[buzz1939]

I got the same response. It struck me as somewhere between unlikely and impossible - what do people think?

Back to the power rating for a minute, it's listed at 100W in the title, but that's probably at 10% THD or something. Spec is 75W / ch with 1% THD into 4 ohms. And typically that's an exaggerated number, under ideal conditions (at the frequency that gives the highest output), rounded up.

BTW, any thoughts on how to bridge this? Nothing that will short it out, since I'd be stupid enough to try it without knowing what I was doing.

[theAnonymous1]

Originally posted by buzz1939
BTW, any thoughts on how to bridge this? Nothing that will short it out, since I'd be stupid enough to try it without knowing what I was doing.

It is already bridged, hence the single supply and two inductors per channel.

You might be able to parallel the channels for more current with low impedance loads.

[audio1st]

I removed the heatsink on my amp and yes, it is just a metal plate on show, no marks. No paste was used so no mess.
If you use the terminal block input terminals, then you bypass the 0.7uf input caps. No caps via this input..
There seems to be a constant background hiss from all channels, at all volume settings. I have tried different power supplies and it is still there..I dont think, IMHO, it is going to be a "hifi amp" ..

[Bearman]

I bet it is those inductors making the hiss. I wonder if they were shielded, it would make some difference.

[Neil Davis]

Originally posted by Ouroboros
Almost certainly a Sanyo STK428-xxx 'Ice-Power' module.

No such luck. Mine finally came today, so off went the heatsink and then on to desoldering the pins.

Here is what it says on the underside of the chip:


SDA-754
SS 07 08 31 15: 09: 25 5128
AC/HOT OK JUN SUN OK

My guess is that it is a module made for them by Monolithic Power. Sure-electronics has an amp board with the MP7220, and this looks like it could be a module made from 4 MP7782's. The MP stuff uses a single supply with analog input, and MP is one of the few that provides that combination.

[kellyinvestor]

Originally posted by Neil Davis


No such luck. Mine finally came today, so off went the heatsink and then on to desoldering the pins.

Here is what it says on the underside of the chip:


SDA-754
SS 07 08 31 15: 09: 25 5128
AC/HOT OK JUN SUN OK

My guess is that it is a module made for them by Monolithic Power. Sure-electronics has an amp board with the MP7220, and this looks like it could be a module made from 4 MP7782's. The MP stuff uses a single supply with analog input, and MP is one of the few that provides that combination.

Umm, did you listen to it first? Good, bad?

[Neil Davis]

Originally posted by kellyinvestor



Umm, did you listen to it first?

Of course not. I'm an engineer.

But I think I was able to put it back together OK (one broken pin that I was able to fix). I'll clean off the solder flux tomorrow, check for damage and try it out sometime in the next few days.